Mitsubishi Galant 9G. Manual — part 1404

SERVICE PRECAUTIONS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-26

SERVICE PRECAUTIONS

M1524000300499

DANGER

•

In order to avoid injury to yourself or others from
accidental deployment of the air bag during servic-
ing, read and carefully follow all the precautions
and procedures described in this manual.

•

After disconnecting the battery cable, wait 60 sec-
onds or more before proceeding with the following
work. The SRS system is designed to retain
enough voltage to deploy the air bag for a short
time even after the battery has been disconnected,
so serious injury may result from unintended air
bag deployment if work is done on the SRS system
immediately after the battery cables are discon-
nected.

WARNING

•

Battery posts, terminals and related accessories
contain lead and lead compounds. WASH HANDS
AFTER HANDLING.

•

Do not use any electrical test equipment on or near
the SRS components, except those specified on

P.52B-347

.

•

Never Attempt to Repair the Following Compo-
nents: SRS-ECU, Clock Spring, Air Bag Module,
Front impact sensor, Side Impact Sensor, Seat Belt
with Pre-tensioner, Seat slide sensor, Front seat
assenbly. If any of these components are diag-
nosed as faulty, they should only be replaced, in
accordance with the INDIVIDUAL COMPONENT
SERVICE procedures in this manual, starting on

P.52B-353

.

•

Do not attempt to repair the wiring harness con-
nectors of the SRS. If any of the connectors are
diagnosed as faulty, replace the wiring harness. If
the wires are diagnosed as faulty, replace or repair
the wiring harness according to the following
table.

.

ACX00583

INSULATING TAPE

BATTERY

BATTERY CABLE (–)

AC

63

55

51

69

61

66

58

65

64

56 57

68

60

67

59

70

62

53

52 B

A

54

A

B

18

10

15

7

13

5

14

6

16

8

17

9

19

11

20

12

1 2

3 4

42

31

38

27

21

41

28

39

22

30

25

47

36

33

44

34

45

37

48

26

29

23

40

32

43

35

46

24

B

A

AC3001278AB

SRS-ECU CONNECTOR

SERVICE PRECAUTIONS

TSB Revision

SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-27

SRS-ECU TERMINAL
NO.

DESTINATION OF HARNESS

CORRECTIVE ACTION

1, 2

Floor wiring harness

→ Seat slide

sensor

Correct or replace the floor wiring
harness.

3

Floor wiring harness

→ Driver’s seat

belt switch for N/C terminal

Correct or replace the floor wiring
harness.

4

Floor wiring harness

→ Driver’s seat

belt switch for COM terminal

Correct or replace the floor wiring
harness.

7, 8

Floor wiring harness

→ Seat belt

pre-tensioner (LH)

Correct or replace the floor wiring
harness.

9*, 10*

Floor wiring harness

→ Side-airbag

module (LH)

Correct or replace the floor wiring
harness.

18

Floor wiring harness

→ Driver’s seat

belt switch for N/O terminal

Correct or replace the floor wiring
harness.

19*, 20*

Floor wiring harness

→ Side impact

sensor (LH)

Correct or replace the floor wiring
harness.

21

Floor wiring harness

→ Instrument

panel wiring harness

→ Air bag off

indicator light

Correct or replace each wiring harness.

23

Floor wiring harness

→ Instrument

panel wiring harness

→ Junction block

(fuse No.22)

Correct or replace each wiring harness.

24

Floor wiring harness

→ Instrument

panel wiring harness

→ Junction block

(fuse No.23)

Correct or replace each wiring harness.

27, 28

Floor wiring harness

→ Instrument

panel wiring harness

→ Air bag module

(Front passenger's side) <1st squib
side>

Correct or replace each wiring harness.

30, 31

Floor wiring harness

→ Instrument

panel wiring harness

→ Air bag module

(Front passenger's side) <2nd squib
side>

Correct or replace each wiring harness.

32

Can line

Correct or replace can line.

33, 34

Floor wiring harness

→ Instrument

panel wiring harness

→ Clock spring →

Air bag module (Driver's side) <2nd
squib side>

Correct or replace each wiring harness.
Replace the clock spring.

36, 37

Floor wiring harness

→ Instrument

panel wiring harness

→ Clock spring →

Air bag module (Driver's side) <1st
squib side>

Correct or replace each wiring harness.
Replace the clock spring.

38, 39

Floor wiring harness

→ Instrument

panel wiring harness

→ Front wiring

harness

→ Front impact sensor (LH)

Correct or replace each wiring harness.

40

Floor wiring harness

→ Ground

Correct or replace the floor wiring
harness.

SERVICE PRECAUTIONS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-28

NOTE: *Vehicles with side-airbags

.

42

Floor wiring harness

→ Instrument

panel wiring harness

→ Seat belt

warning light

Correct or replace each wiring harness.

43

Can line

Correct or replace can line.

47, 48

Floor wiring harness

→ Instrument

panel wiring harness

→ Front impact

sensor (RH)

Correct or replace each wiring harness.

51

Floor wiring harness

→ Passenger’s

seat belt switch for COM terminal

Correct or replace the floor wiring
harness.

52

Floor wiring harness

→ Passenger’s

seat belt switch for N/C terminal

Correct or replace the floor wiring
harness.

57*, 58*

Floor wiring harness

→ Side-airbag

module (RH)

Correct or replace the floor wiring
harness.

59, 60

Floor wiring harness

→ Seat belt

pre-tensioner (RH)

Correct or replace the floor wiring
harness.

63*, 64*

Floor wiring harness

→ Side impact

sensor (RH)

Correct or replace the floor wiring
harness.

65

Floor wiring harness

→ Passenger’s

seat belt switch for N/O terminal

Correct or replace the floor wiring
harness.

66

Floor wiring harness

→ Occupant

classification sensor

Correct or replace the floor wiring
harness.

SRS-ECU TERMINAL
NO.

DESTINATION OF HARNESS

CORRECTIVE ACTION

SRS AIR BAG DIAGNOSIS

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SUPPLEMENTAL RESTRAINT SYSTEM (SRS)

52B-29

WARNING

•

Inspection of the SRS-ECU connector harness
should be carried out by the following procedure.
Insert the backprobing tool into connector from
harness side (rear side), and connect the tester to
backprobing tool. If any tool other than backprob-
ing tool is used, it may cause damage to the har-
ness and other components. Furthermore,
measurement should not be carried out by touch-
ing the backprobing tool directly against the termi-
nals from the front of the connector. The terminals
are plated to increase their conductivity, so if they
are touched directly by the backprobing tool, the
plating may break, which will decrease reliability.

•

The SRS components and seat belt with pre-ten-
sioner should not be subjected to heat, so remove
the SRS-ECU, driver’s and front passenger’s air
bag modules, clock spring, side-airbag modules,
and seat belt pre-tensioner before drying or baking
the vehicle after painting.

•

SRS-ECU, air bag module, clock spring: 93

°

C

(200

°

F) or more

•

Seat belt with pre-tensioner 90

°

C (194

°

F) or

more

•

After servicing the SRS system, check the warning
light operation to make sure that the system func-
tions properly. (Refer to

P.52B-3

).

•

Make certain that the ignition switch is in the
"LOCK"(OFF) position when the scan tool is con-
nected or disconnected.

SRS AIR BAG DIAGNOSIS

INTRODUCTION TO DIAGNOSIS

M1524005000330

The SRS system is controlled by the SRS-ECU. The
SRS-ECU judges how severe a collision is by detect-
ing signals from the left and right front impact sen-
sors and side impact sensors, front air bag analog
G-sensor and front air bag safing G-sensor and
side-airbag safing G-sensor. If the impact is over a
predetermined level, the SRS-ECU sends an ignition
signal. At this time, if the safing G-sensor is on, the
SRS air bag will inflate. (The passenger's air bag
may not inflate according to the occupant detection
data from the occupant classification-ECU.) The

SRS warning light in the combination meter alerts a
malfunction of the SRS system. If the following
symptoms occur even when the vehicle has not been
in a collision, there may be a malfunction in the SRS
system.

• The SRS warning light does not go off within

approximately seven seconds after the ignition
switch has been turned to the "ON" position.

• The SRS warning light does not illuminate when

the ignition switch is turned to the "ON" position.

Refer to Post-collision Diagnosis when inspecting
and servicing a vehicle that has been in a collision
(Refer to

P.52B-348

).

AC307379

AC301599

AC300928

SRS-HARNESS CONNECTOR

SRS-ECU HARNESS CONNECTOR
(REAR SIDE)

AB